Desperately need introductory CIRCUIT/RESISTOR help

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Homework Help Overview

The problem involves creating a circuit with a 12.0V battery and three 10.0Ω light bulbs, aiming to achieve brightness levels that are multiples of 1, 2, and 3. Participants are exploring the relationship between resistance, voltage, and power in the context of circuit design.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the use of parallel circuits and question how to achieve the desired brightness ratios using the given resistors and bulbs. There is uncertainty about the definition of brightness and its relationship to power. Some participants suggest approximating the ratios due to the abundance of resistors.

Discussion Status

The discussion is ongoing, with participants sharing hints and exploring different configurations. There is no clear consensus, but some guidance has been offered regarding the use of parallel circuits and the interpretation of brightness in terms of current rather than voltage.

Contextual Notes

Participants note constraints such as the lack of clarity on the definition of brightness and limitations imposed by the software used for circuit design, which restricts the number of resistors that can be included in a configuration.

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Homework Statement


You’re given a 12.0V battery, 3 light bulbs (of 10.0Ω each), and LOTS of 10.0Ω resistors. Make a circuit so that the light bulbs’ brightnesses are multiples of 1, 2, 3. In other words, if the dimmest light bulb has brightness B, the second dimmest will have brightness 2B, and the brightest will be 3B.

Homework Equations



I've derived a few over a few hours and have drawn it out and mapped and graphed v^2/r (I'm assuming in this case brightness means POWER which is vsquared over r)

The Attempt at a Solution


I just don't see how this is possible to actually map out these 10 ohm resistors with a 10 ohm bulb and a set 12 volt battery. I am under the presumption that by brightness my teacher means power, and having graphed the voltages after crossing a list of quantities of 10 ohm resistors, I cannot find 3 powers that are direct multiples of 2 and 3 of one resistor configuration.

Note that there is no statement for what we are defining as brightness, we have not been taught anything about brightness and that's actually the first time the word has popped up in this course. I don't understand because under my understanding, anything you can construct on a resistor circuit is not linearly related to the brightness, but rather the measurement of lumens of the bulb. Would appreciate if anoyne helped
 
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hi martinlematre! :smile:

hint: parallel :wink:
 
tiny-tim said:
hi martinlematre! :smile:

hint: parallel :wink:

I am using parallel circuits. The powers (V^2 over Resistors) are not linearly scaling with 10 ohm resistors
 
?? :confused:

V will be the same for parallel circuits
 
tiny-tim said:
?? :confused:

V will be the same for parallel circuits

There's a voltage drop across a resistor whose specific quantity is proportional to power (What I'm assuming is what my teacher means by brightness).

V^2/R will be the variable Voltage after drops (And before each lightbulb) squared, over 10ohms (The lightbulb.

Except there is no configuration where that variable voltage after going through X resistors has a 1, 2x and 3x value for power
 
martinlematre said:
Except there is no configuration where that variable voltage after going through X resistors has a 1, 2x and 3x value for power

the question says "LOTS" of resistors, so i think you're expected to get only approximately 1:2:3 :wink:

(and it would be more logical to use I, not V)
 
tiny-tim said:
the question says "LOTS" of resistors, so i think you're expected to get only approximately 1:2:3 :wink:

(and it would be more logical to use I, not V)

except I am expected to draw/use a very limited program where i can't fit more than 5 or 6 resistors in a circuit without it crashing.

im just making brightness proportional to I.
 
Suppose you had 3 light bulbs in series across the 12 volt battery.

Then you rewire the circuit to have 1 light bulb in series with two 10 ohm resistors.

Would the first circuit be exactly 3 times as bright as the second?
 

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